超细电气石粉体的表面改性试验研究

超细电气石粉体在使用基体中的分散性直接影响其释放负氧离子的性能.本文以提高超细电气石粉体在亲水性体系中的分散性为目的进行了表面改性研究.通过对超细电气石粉体的聚丙烯酸改性处理,并通过对改性前后的样品进行红外光谱分析分析了改性机理.结果表明,对超细电气石粉体进行表面改性时,聚丙烯酸的最优用量为电气石粉体质量的1.0%,改性处理后样品在水中的分散性大大提高.红外光谱分析表明,聚丙烯酸与电气石粉体表面的结合方式为化学吸附.     

电气石/LLDPE复合材料的制备及性能研究

用钛酸酯对电气石进行表面改性,将改性后的电气石与线性低密度聚乙烯(LLDPE)共混,采用挤出造粒、注塑成型工艺,制备电气石/LLDPE复合材料。对复合材料进行了性能测试。测试结果表明,当电气石添加量为2%时,复合材料的拉伸强度和缺口冲击强度都达到最大值,此时拉伸强度比未添加电气石的LLDPE的拉伸强度提高了2. 8%,缺口冲击强度提高了46. 0%,且复合材料可释放负离子,具有空气净化功能。     

月桂酰氯对电气石的表面改性及其结构表征

以月桂酰氯为改性剂对电气石的表面进行改性,以活化指数和接触角为参数考察了反应条件对电气石改性效果的影响.结果表明,当质量比为1∶1的电气石与月桂酰氯在DMF溶剂中80℃下反应5h时,改性电气石的活化指数可达96％,所得改性电气石表面具有良好的疏水性;结构分析表明,电气石表面接枝上了疏水性的烷基,但没有影响电气石的晶体结构.     

负离子释放型PBAT功能复合材料的研究

以生物可降解塑料聚己二酸/对苯二甲酸丁二酯(PBAT)为连续相基体、电气石粉为分散相,用改性剂山梨醇酐单硬脂酸酯对电气石粉进行表面有机改性,采用湿法熔融共混法制备了PBAT/电气石粉复合材料,探讨了不同工艺条件下改性电气石粉在PBAT中的分散效果,并对PBAT/电气石粉复合材料的力学性能、热稳定性能和负离子释放量进行了考察。结果表明,添加适量的改性电气石粉可以提高PBAT的力学性能,当改性电气石粉添加量为PBAT质量的3%时,PBAT/改性电气石粉复合材料的拉伸强度和断裂伸长率均达到最大值,分别为30.9 MPa和844%,差示扫描量热分析表明,改性电气石粉对PBAT起到异相成核的作用,提高了PBAT的结晶峰温度和结晶度,负离子释放量测试表明,PBAT/改性电气石粉复合材料具有优异的负离子释放功能,当改性电气石粉添加量为PBAT质量的7%时,复合材料的负离子释放量达到了460个/cm3。     

纳米电气石/聚丙烯驻极熔喷非织造布的研制

研制了一种纳米电气石改性驻极体熔喷聚丙烯非织造布母粒,并采用电晕放电法制备出纳米电气石/聚丙烯驻极熔喷非织造布。探讨了纳米电气石在聚丙烯树脂中的分散状况及改性母粒的流变性能,同时对非织造布力学性能、表面电荷密度和过滤性能进行了测试。结果表明:电气石能较好地分散在聚丙烯树脂中;加入特种电气石之后,纤网的机械性能有所下降;驻极体熔喷非织造布的驻极效果大大改善,其表面电荷密度、过滤性能均有明显提高。     

负离子功能PET纤维的研制

选择超细电气石粉末作为新型功能添加剂,通过偶联剂表面修饰,对改性效果进行比较和表征,并制备了负离子功能聚酯纤维。研究了超细电气石粉末的表面改性及其在高分子基体中的分散性,以及PET共混体系和负离子功能纤维的性能。主要研究结果如下:对超细电气石粉末的表面改性,采用单烷氧型钛酸酯5%处理量的处理效果较佳,在普通纺丝速度范围内,PET共混体系的可纺性与PET一样稳定。经测试,试验纤维具有良好的物理机械性能和负离子发射功能(大于4500个/cm3)。     

电气石改性研究

为了增强电气石与有机聚合物的相容性和分散性,对电气石进行了表面改性。用甲苯做溶剂,以钛酸酯做改性剂对电气石进行表面改性,得到疏水性电气石粉体;并对改性电气石进行了活化指数、接触角、亲油化度测试,主要研究了球磨时间,改性剂用量,反应时间,反应温度,固液比对电气石改性效果的影响,确定了电气石粉体表面改性的较好的实验条件。     

阴离子热反应性聚丙烯酸酯/环氧硅氧烷无皂乳液对纸张的表面改性

以环氧硅氧烷作交联剂,聚乙烯醇(PVA)为高分子胶体稳定剂,采用无皂种子聚合制备了改性聚丙烯酸酯表面施胶剂.当w(AM-MAA)=8%～10%,软硬单体比例n(BA)n(St)=1.2,w(PVA)=2%～3%,w(环氧硅氧烷)=2%时,改性聚丙烯酸酯具有优异的施胶效果;以质量分数为1.0%的聚合物乳液进行表面施胶时,纸张施胶度可达9.68 s,表面强度达3.8 m/s.     

新型聚丙烯酸酯乳液对纳米氢氧化镁的改性研究

为使纳米氢氧化镁的表面性质由亲水性变为亲油性,以使其在高聚材料中能够更好地分散填充并减少团聚,采用新型纳米聚丙烯酸酯乳液作为改性剂,对纳米氢氧化镁进行了表面改性研究。采用活化指数测试、接触角测试、红外光谱分析及热重分析等手段研究了改性纳米氢氧化镁的结构和性能。结果表明,在改性剂添加量（改性剂与纳米氢氧化镁的质量比）为0.6时,纳米氢氧化镁的表面性质由亲水疏油转变为亲油疏水,新型纳米聚丙烯酸酯乳液与纳米氢氧化镁粒子表面发生了化学反应,并包覆在其表面,达到了较好的改性效果。对比了其他传统型硅烷偶联剂对纳米氢氧化镁的改性效果,结果表明新型聚丙烯酸酯微乳液改性的纳米氢氧化镁的分散性和疏水亲油性都要优于传统型硅烷偶联剂的改性效果。     

含硅聚氨酯预聚体改性聚丙烯酸酯清漆的制备与研究

采用端羟基聚硅氧烷、功能单体与异佛尔酮二异氰酸酯缩聚制备新型含硅聚氨酯预聚体(Si-PU),Si-PU与丙烯酸酯单体共聚,得到Si-PU改性聚丙烯酸酯。以改性聚丙烯酸酯为成膜物质,以异氰酸酯基树脂为固化剂按基团等物质的量比配制成双组分清漆,并制备涂膜。采用FT-IR对改性前后聚丙烯酸酯结构进行了表征。研究了Si-PU用量对聚丙烯酸酯清漆的黏度、耐热性、附着力及其涂膜绝缘性的影响。FT-IR表明,Si-PU已经接枝到了丙烯酸酯共聚物的骨架中。Si-PU质量分数在0～15%,涂膜的附着力不变,且Si-PU用量为聚丙烯酸酯的15%时,得到综合性能良好的含硅聚氨酯改性聚丙烯酸酯清漆。     

Effect of clay on mechanical and gas barrier properties of blown film LDPE/clay nanocomposites

Low density polyethylene (LDPE)/clay nanocomposites, which can be used in packaging industries, were prepared by melt‐mix organoclay with polymer matrix (LDPE) and compatibilizer, polyethylene grafted maleic anhydride (PEMA). The pristine clay was first modified with alkylammonium salt surfactant, before melt‐mixed in twin screw extruder attached to blown‐film set. D‐spacing of clay and thermal behavior of nanocomposites were characterized by Wide‐Angle X‐ray Diffraction (WAXD) and differential scanning calorimetry (DSC), respectively. WAXD pattern confirmed the increase in PEMA contents exhibited better dispersion of clay in nanocomposites. Moreover, DSC was reported the increased PEMA contents caused the decrease in degree of crystallinity. Mechanical properties of blown film specimens were tested in two directions of tensile tests: in transverse tests (TD tests) and in machine direction tests (MD tests). Tensile modulus and tensile strength at yield were improved when clay contents increased because of the reinforcing behavior of clay on both TD and MD tests. Tensile modulus of 7 wt % of clay in nanocomposite was 100% increasing from neat LDPE in TD tests and 17% increasing in MD tests. However, elongation at yield decreased when increased in clay loading. Oxygen permeability tests of LDPE/clay nanocomposites also decreased by 24% as the clay content increased to 7 wt %. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

不同形态矿物复合增强LDPE的研究

利用硅灰石、白云母和珍珠岩等3种具有特殊晶体结构和形态的矿物粉体,进行表面改性处理,与低密度聚乙烯(LDPE)复合加工制备复合材料。结果表明,甲基丙烯酰氧基三甲氧基硅烷对3种矿物粉体的改性效果较好;在总用量为30%,硅灰石∶白云母∶珍珠岩为1∶1∶1时,复合材料的强度、耐磨性、流动性都得到增强,复合材料性能优于纯LDPE。     

纳米聚丙烯酸酯改性纳米Mg(OH)_2及其在LDPE中的应用

采用纳米聚丙烯酸酯乳液改性纳米Mg(OH)2,通过单螺杆挤出机制备了纳米Mg(OH)2/低密度聚乙烯(LDPE)复合材料,利用红外光谱、扫描电镜、透射电镜等方法对改性前后的Mg(OH)2及Mg(OH)2/LDPE复合材料进行了表征。结果表明:纳米Mg(OH)2表面经纳米聚丙烯酸酯乳液改性后吸附上了一层聚丙烯酸酯;纳米聚丙烯酸酯乳液改性提高了纳米Mg(OH)2的热稳定性,分解温度提高了27℃;改性纳米Mg(OH)2在LDPE基体中分散更为均匀;改性纳米Mg(OH)2的用量为LDPE的15%时复,合材料的拉伸强度比纯LDPE提高了6.5%。     

改性木聚糖对PBAT/PLA复合材料包装性能的影响

通过硅烷偶联剂KH560对木聚糖（xylan）进行改性，采用熔融共混制备聚己二酸/对苯二甲酸丁二酯（PBAT）/聚乳酸（PLA）/xylan复合薄膜，探讨了不同含量的xylan和改性木聚糖（s-xylan）对薄膜的力学性能和透氧、透湿、透光等性能的影响。结果表明，复合薄膜的拉伸强度和氧气透过率在当s-xylan含量为1 %（质量分数，下同）时达到最佳效果，其中拉伸强度较纯PBAT/PLA薄膜提高了11.7 %，氧气透过率比纯PBAT/PLA薄膜的氧气透过系数降低了32.7 %；s?xylan复合薄膜的阻湿能力明显优于未改性xylan复合薄膜，同时复合薄膜雾度随着xylan含量的增加而增大。     

Characterization and properties of LDPE film with gallic‐acid‐based oxygen scavenging system useful as a functional packaging material

We prepared and characterized active, oxygen‐scavenging, low density polyethylene (LDPE) films from a non‐metallic‐based oxygen scavenging system (OSS) containing 1, 3, 5, 10, and 20% of gallic acid (GA) and potassium chloride (PC). We compared the surface morphology and mechanical, permeability, and optical properties of the oxygen‐scavenging LDPE film with those of pure LDPE film. The surface morphology, gas barrier, and thermal properties indicate that the OSS was well incorporated into the LDPE film structure. The surface roughness of the film increased with the amount of oxygen scavenging material. The oxygen and water vapor permeability of the developed film also increased with the amount of oxygen scavenging material, though its elongation decreased. The oxygen scavenging capability of the prepared film was analyzed at different temperatures. The initial oxygen content (%) in the vial headspace, 20.90%, decreased to 16.6% at 4 °C, 14.6% at 23 °C, and 12.7% at 50 °C after 7 days of storage with the film containing 20% OSS. The film impregnated with 20% organic oxygen scavenging material showed an effective oxygen scavenging capacity of 0.709 mL/cm² at 23 °C. Relative humidity triggered the oxygen scavenging reaction. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44138.     

无卤阻燃低密度聚乙烯复合材料的流变性能

采用熔融共混法制备了无卤阻燃低密度聚乙烯(LDPE/FR)复合材料。通过极限氧指数仪和毛细管流变仪等考察了LDPE/FR复合材料的阻燃性能和流变性能。结果表明:随着阻燃剂添加量的增加,LDPE/FR的阻燃性能逐渐提高,当阻燃剂的质量分数为25%时,阻燃体系的极限氧指数达28.3%;LDPE/FR熔体的表观黏度随着阻燃剂添加量的增加以及剪切速率的提升而降低,其非牛顿指数为0.42~0.70,属于典型的假塑性流体。     

Energy transfer to Eu(III) in the solid‐state low‐density polyethylene–poly(acrylic acid) and low‐density polyethylene–Fe2O3–poly(acrylic acid) matrices

Ion exchange between H⁺ and Eu³⁺ and/or Tb³⁺ was studied in the material modified by in situ sorption and thermal polymerization of acrylic acid in low‐density polyethylene (LDPE–PAA) and in the composite system LDPE–Fe₂O₃–PAA. Fluorescence spectroscopy showed evidence of Eu³⁺ and/or Tb³⁺ ion exchanges in these materials. The matrix LDPE–PAA after Eu(III) ion exchange presented luminescence (excitation 265 nm). This was explained by an energy‐transfer process from the matrix LDPE–PAA to Eu³⁺ ions. The LDPE–PAA matrix after simultaneous Eu³⁺/Tb³⁺ ion exchange exhibited Eu³⁺ and Tb³⁺ ion luminescence (excitation 265 nm), confirming an energy‐transfer process from LDPE–PAA to Eu³⁺ ions in LDPE–PAA–Eu³⁺–Tb³⁺ matrix. Fe₂O₃ in LDPE–Fe₂O₃–PAA quenched the matrix for excitation at 265 nm and no emission at the region 400 nm was observed. The luminescence of Tb³⁺ ions in the matrix LDPE–Fe₂O₃–PAA–Tb³⁺ (excitation 265 nm) was partially quenched by Fe₂O₃. However, a weak emission of Eu³⁺ ions was observed (excitation 265 nm) in the matrix LDPE–Fe₂O₃–PAA after simultaneous Eu³⁺ and Tb³⁺ ion exchanges, suggesting an energy transfer from Tb³⁺ to Eu³⁺ ions. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 919–931, 2000     

LLDPE/LDPE/TiO2复合膜的分散及光学性能

讨论了纳米TiO2在线型低密度聚乙烯（LLDPE），低密度聚乙烯（LDPE）复合体系中的分散和体系流变行为，研究了复合薄膜的光学性能。结果表明，以高流动性LDPE为基体的纳米TiO2母料，加入LLDPE，LDPE体系中后。复合体系的表观粘度有所提高。但拉伸粘度显著下降。纳米TiO2母料在LLDPE／LDPE复合体系中具有良好的分散性，复合薄膜中的纳米TiO2为一次粒子。纳米TiO2起到了异相成核剂的作用。球晶的粒子得到细化。在本研究的纳米填充范围内（质量分数不大于1.0％），复合薄膜的透光度基本不变。雾度发生了较大幅度上升，复合薄膜在紫外光区域的吸收显著增强。     

表面改性对LDPE/nano-ATH复合材料性能的影响

采用熔融共混法制备了低密度聚乙烯(LDPE)/纳米氢氧化铝(nano-ATH)复合材料,研究了nano-ATH表面改性前后对复合材料力学性能和阻燃性能的影响;利用扫描电镜(SEM)分析了nano-ATH表面改性前后在LDPE基体中的分散性。结果表明:表面改性nano-ATH使复合材料具有较高的拉伸强度和断裂伸长率;nano-ATH用量较少时,其表面改性与否对复合材料的阻燃性能基本没有影响;加入量较大时,表面改性nano-ATH使复合材料具有较好的阻燃性能,其在LDPE基体中的分散性也得到改善。     

Bio- and bioelectro-catalytic properties of polyaniline/poly(acrylic acid) composite films bearing covalently-immobilized acid phosphatase

Conducting films composed of polyaniline (PANI) and poly(acrylic acid) (PAA) were prepared by electrochemical polymerization of aniline in the presence of various concentrations of PAA. The content of PAA moiety on the surface of the composite films (PANI/PAA films) was estimated by determination of carboxyl groups and found to be controlled by the concentration of PAA in polymerization solution. Acid phosphatase (ACP) was immobilized covalently on the PANI/PAA films by the condensation reaction with the carboxyl groups on the films. It was confirmed that the enzyme activity of the ACP-immobilized PANI/PAA film increased with increasing content of PAA moiety on the surface of the film, accompanying an increase in the amount of the immobilized ACP. The activity of the covalently immobilized ACP was significantly higher than that of the ACP adsorbed on the PANI/PAA film. By use of the ACP-immobilized PANI/PAA film as an enzyme electrode, bioelectrocatalytic oxidation of L-ascorbic acid 2-phosphate (ASA2P) was examined. The enzyme electrode gave the current due to the oxidation of ASA2P in proportion to the content of PAA moiety on the surface of the PANI/PAA film used, which was relevant to the activity of the covalently immobilized ACP.